alikeness vs synonymia

alikeness

noun
  • The result or product of being alike. 

  • The state or quality of being alike. 

synonymia

noun
  • The use of two or more synonyms together to amplify or explain a given subject or term. A kind of repetition that adds force. 

How often have the words alikeness and synonymia occurred in a corpus of books? (source: Google Ngram Viewer )